The Rosebud Indian Reservation was established in 1889 by the United States' partition of the Great Sioux Reservation. Created in 1868 by the Treaty of Fort Laramie, the Great Sioux Reservation originally covered all of West River, South Dakota (the area west of the Missouri River), as well as part of northern Nebraska and eastern Montana. The reservation includes all of Todd County, South Dakota and communities and lands in the four adjacent counties, which had at one time been entirely part of the reservation.

The RIR is located in south central South Dakota, and presently includes within its recognized border all of Todd County, an unincorporated county of South Dakota. However, the Oyate also has communities and extensive lands and populations in the four adjacent counties, which were once within the Rosebud Sioux Tribe (RST) boundaries: Tripp, Lyman, Mellette, and Gregory Counties, all in South Dakota. Mellette County, especially, has extensive off-reservation trust land, comprising 33.35 percent of its land area, where 40.23 percent of the population lives.

The Oyate capital is the unincorporated town of Rosebud, established when the Spotted Tail Indian Agency (named after the 19th-century war chief, whose Lakota name was Sinte Gleska) was moved from northwestern Nebraska to the banks of Rosebud Creek near its confluence with the Little White River. The largest town on the reservation is Mission, located at the intersections of US Highways 18 and 83.

Mission's near neighbor of Antelope is one of the many tribal band communities established in the late 1870s and growing since then. Other major towns in the reservation are Saint Francis, located southwest of Rosebud and the home of Saint Francis Indian School, a private Catholic institution first established as a mission school. Saint Francis, with a current population of about 2000, is the largest incorporated town in South Dakota without a state highway for access.

Located on the Great Plains, just north of the Nebraska Sandhills, Rosebud Indian Reservation has large areas of Ponderosa Pine forest scattered in its grasslands. Deep valleys are defined by steep hills and ravines, often with lakes dotting the deeper valleys.

The RST owns and operates Rosebud Casino, located on U.S. Route 83 just north of the Nebraska border. Nearby is a fuel plaza, featuring truck parking and a convenience store. Power for the casino is furnished in part by one of the nation's first tribally owned electricity-generating wind turbines. The tribe allows alcohol sales on the reservation, which enables it to keep the sales taxes and other revenues generated, as well as to police and regulate its use. A new residential development, Sicangu Village, was recently built along Highway 83 near the casino and the state line.

The RST population is estimated at 25,000 (2005). It is served by the Oyate administration and agencies, as well as the BIA Rosebud Agency, Todd County School District, Saint Francis Indian School, the Rosebud Indian Health Service Hospital, and Sinte Gleska University. The tribal university is named after the 19th-century Sioux war chief and statesman, whose name in English was Spotted Tail.

Under the Indian Reorganization Act of 1934, the federally recognized Rosebud Sioux Tribe (RST) re-established self-government, after adopting a constitution and bylaws, to take back many responsibilities for internal management from the BIA. It followed the model of elected government: president, vice-president, and representative council, adopted by many Native American nations. At the time and since then, many tribal members opposed the elected government, preferring their traditional form of clan chiefs selected for life, contingent on approval by women elders, and a tribal council that operated by consensus .[citation needed]

The elders of both men and women have continued to have influence within the nation, particularly among those who have followed more traditional lives. At times the political factions have developed and continued along ethnic and cultural lines, with full-blood Sioux following traditional ways. Others, sometimes of mixed-blood or having had more urban or European-American experiences, support the elected government.

The short two-year terms of office can make it difficult for elected officials to carry out projects over the long term. In addition, BIA officials and police retain roles on the reservations, which the historian Akim Reinhardt calls a form of "indirect colonialism".[3]

Janeen Antoine (Sicangu Lakota), curator, educator, and founder in 1983 of the American Indian Contemporary Arts in San Francisco, grew up on the Rosebud Reservation. Her gallery was one of the first in the nation to feature contemporary American Indian art and is important in encouraging new work.[2]

Benjamin "Ben" Reifel (Rosebud Sioux) (1906-1990), five-term U.S. Congressman, was born near Parmelee. He served in the U.S. Army, worked as a field officer and regional administrator for the BIA, and earned master's and doctoral degrees in public administration from Harvard University. Reifel was elected as US Representative in 1960 and served until his retirement in 1971.

Yvette Roubideaux (Rosbud Sioux), M.D., M.P.H., is Director of the Indian Health Service (IHS), appointed in 2009 as the first woman to hold the position.

Chief Sinte Gleska, translated as "Spotted Tail", a Brulé Sioux (1823-1881) a relative of Crazy Horse, was a leading war chief in battles with the Pawnee. He later became a leader of the peace faction and a statesman of the Sioux tribe. In 1868 Spotted Tail signed a treaty with the US ceding Sioux lands along the Republican and the Platte rivers.

Paul Eagle Star, (1864-1891) (Brulé Sioux). He attended Carlisle Indian Industrial School, enrolling in November 1882 and left the school six years later. He worked in the blacksmith shop at Rosebud Agency in July 1889. Two years later, Eagle Star was recruited and worked under contract to perform in Buffalo Bill's Wild West Show, which toured in England. He died a few days after breaking his ankle when he fell off a horse in Sheffield. He was buried at West Brompton's cemetery. In March 1999 his remains were exhumed for transport and reburial in Rosebud's Lakota cemetery. Tribal descendants include two grandchildren, Moses and Lucy Eagle Star II.

Chief Iron Shell, who led the Brulé Orphan Band during the Powder River War of 1866-1868.

In United States v. Sioux Nation of Indians, the people of the Rosebud Sioux Reservation joined the Oglala Lakota and other Sioux nations in suing the federal government in a land claim for its taking of the Black Hills. In 1980 the case was heard by the United States Supreme Court, which agreed with the nations that the US had acted illegally in 1877. The US government offered financial compensation, which the Sioux have refused. They still demand the return of the land to their nation. The compensation fund is earning interest and has increased in value.